Conventionally, in a computer or a mobile device, a video image is displayed on a display screen by a video image processing device called GPU (Graphics Processing Unit) (see, for example, Patent Literature 1 (PTL 1)).
PTL 1 discloses a display device in which the number of sub-frames that constitute one frame is determined according to a set on-duty ratio. Then, display driving is performed based on the determined number of sub-frames.
Also, in recent years, the video image display rate on a display screen is determined increasingly by the GPU performance.